The present invention generally relates to treatment of wounds, and more specifically to improved apparatus and methods for treating a wound or a portion of a wound on a body by applying reduced pressure to the body at the site of the wound. In this context, the terms “wound” and “body” are to be interpreted broadly, to include any wound, body, or body part that may be treated using reduced pressure.
The treatment of open or chronic wounds that are too large to spontaneously close or otherwise fail to heal by means of applying reduced pressure to the site of the wound is well known in the art. One such system is disclosed in U.S. patent application Ser. No. 10/652,100, which was filed with the U.S. Patent and Trademark Office on Aug. 28, 2003 and published as U.S. Publication No. 2004/0073151 A1. The disclosure of this U.S. patent application is incorporated herein by reference. Another system is disclosed in U.S. patent application Ser. No. 11/026,733, entitled “Improved Reduced Pressure Wound Treatment Appliance,” which was filed with the U.S. Patent and Trademark Office on Dec. 30, 2004, now U.S. Pat. No. 7,128,735. The disclosure of this U.S. patent application is also incorporated herein by reference. Yet another system is disclosed in U.S. patent application Ser. No. 11/064,813, entitled “Improved Flexible Reduced Pressure Wound Treatment Appliance,” which was filed with the U.S. Patent and Trademark Office on Feb. 24, 2005 and published as U.S. Publication No. 2005/0261642 A1. The disclosure of this U.S. patent application is also incorporated herein by reference.
Reduced pressure wound treatment systems currently known in the art commonly involve placing a treatment device that is impermeable to liquids over the wound, using various means to seal the treatment device to the tissue of the patient surrounding the wound, and connecting a source of reduced pressure (such as a vacuum pump) to the treatment device in a manner so that an area of reduced pressure is created under the treatment device in the area of the wound. The systems also typically act to remove exudate that may be aspirated from the wound. Thus, such systems also typically have a separate collection device located between the reduced pressure source and the treatment device to collect. This collection device represents a separate source of expense in reduced pressure wound treatment. In addition, it is advantageous in some circumstances to remove exudate from the wound so that the exudate does not remain in the presence of the wound. For example, healing of the wound may be enhanced by the removal of exudate from the wound in some circumstances. In yet other cases, it may be advantageous to be able to gain physical access to the wound without having to remove the treatment device from the body surrounding the wound. For example, it may be desirable to monitor or treat the condition of the wound during the treatment process. If the treatment device is sealed to the body using an adhesive tape, removing the adhesive tape to monitor or treat the wound may cause discomfort and pain for the patient.
Therefore, there is a need for a wound treatment device that can eliminate the requirement for a separate collection device to collect exudate from the wound. This type of device could reduce the expense involved in wound treatment by eliminating the need for the collection device. There is also a need for such a treatment device to remove exudate from the presence of the wound to aid in wound healing. It may also be desirable for this type of treatment device to be disposable in certain circumstances. Further, there is a need for a treatment device that would allow for physical access to the wound without the need for removing the treatment device from the body. This type of device could enhance patient comfort. In addition, where the access is simple and quickly obtained, it could also decrease the cost of wound treatment by reducing the time required of healthcare practitioners to be involved in wound treatment. Finally, there is also a need for a reduced pressure treatment system that is relatively inexpensive, while meeting the needs described above.
Reduced pressure wound treatment systems currently known in the art also commonly involve placing a cover that is impermeable to liquids over the wound, using various means to seal the cover to the tissue of the patient surrounding the wound, and connecting a source of reduced pressure (such as a vacuum pump) to the cover in a manner so that an area of reduced pressure is created under the cover in the area of the wound. However, the covers currently known and used in the art have a number of disadvantages. For example, in one version they tend to be in the form of a flexible sheet of material that is placed over the wound and sealed to the surrounding tissue using an adhesive, adhesive tape, or other similar means. As tissue swelling in the area of the wound decreases during the healing process, the adhesive may begin to stretch the surrounding tissue, as well as tissue within the wound, resulting in discomfort and pain to the patient. This may necessitate more frequent cover changes, increasing the time medical staff must expend in treating the wound. This additional time, of course, also tends to increase the expense involved in treating the wound. In addition, these types of covers can typically only be used where there is normal tissue adjacent to the wound to which the adhesive seal can be attached. Otherwise, the seal must be made in a portion of the area of the wound, and exudate from the wound tends to break the seal so that reduced pressure cannot be maintained beneath the wound cover. Thus, such covers (and many other covers requiring adhesive seals) may typically only be used to treat an entire wound, as opposed to only a portion of a wound. Further, the adhesive seal creates discomfort for the patient when the sheet cover is removed. In other versions, the covers tend to be rigid or semi-rigid in nature so that they are held away from the surface of the wound. In these versions, the covers are sometimes difficult to use because the shape and contour of the patient's body in the area of the wound do not readily adapt to the shape of the cover. In such cases, additional time is required for the medical staff to adapt the cover for its intended use. This also increases the expense of wound treatment. In addition, it is also often necessary to use an adhesive, adhesive tape, or other similar means to seal the rigid or semi-rigid cover to the tissue surrounding the wound. In these instances, the same disadvantages discussed above with respect to the first version also apply to this version as well. In still other cases, the rigid and semi-rigid covers must be used with padding in the area where the cover is adjacent to the patient to prevent the edges of the cover from exerting undue pressure on the tissue surrounding the wound. Without the padding, the patient may experience pain and discomfort. The additional padding, which may make the cover itself more expensive, may also take a greater amount of time to place on the patient for treatment purposes. These covers may also have the problem of placing tension on the surrounding tissue as the swelling in the area of the wound decreases during the healing process. In yet another version, covers are constructed of combinations of flexible materials and rigid materials. In these versions, a flexible member, such as a flexible sheet, is typically supported by a rigid or semi-rigid structure that is either placed between the flexible member and the wound or in the area above and outside the flexible member. In either case, the flexible member must usually be sealed to the tissue surrounding the wound using an adhesive, adhesive tape, or other similar means. This seal creates the same problems described above. In addition, the same problems described above with respect to rigid and semi-rigid structures are also often present. In all of the versions described above, it may be difficult to tell if reduced pressure in the area of the wound under the cover has been lost because the cover itself does not generally provide a visual clue of such loss.
Therefore, there is a need for a reduced pressure wound treatment system that has a means to enclose all or a portion of a wound without the need for an adhesive seal. There is also a need for such enclosing means to be flexible, so that it adapts to changing shapes and contours of the patient's body as wound healing progresses. Further, there is a need for an enclosing means that is adaptable to a wide variety of patient body shapes and contours. There is also a need for an enclosing means that is simple to apply to the patient's body, and simple to remove from the patient's body. Such enclosing means would also take less time to apply and remove, reducing the expense involved in wound treatment. There is also a need for an enclosing means that is relatively inexpensive, while meeting the needs described above. In addition, there is a need for an enclosing means that may be used within the wound (or a portion thereof), without the need to seal the enclosing means to normal tissue surrounding the wound. Further, there is a need for an enclosing means that flexes with movement of the portion of the body surrounding the wound, without the need for an adhesive seal or rigid or semi-rigid structure. Finally, there is a need for an enclosing means that provides a visual clue of loss of reduced pressure in the area of the wound under the enclosing means.